The Collaborative International Dictionary of English v.0.48:

Aslant \A*slant"\, adv. & a. [Pref. a- + slant.]
   Toward one side; in a slanting direction; obliquely.
   [1913 Webster]

         [The shaft] drove through his neck aslant. --Dryden.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Aslant \A*slant"\, prep.
   In a slanting direction over; athwart.
   [1913 Webster]

         There is a willow grows aslant a brook.  --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

aslant
    adv 1: over or across in a slanting direction
    2: at an oblique angle; "the sun shone aslant into his face"
       [syn: obliquely, aslant, athwart]
    adj 1: having an oblique or slanted direction [syn: aslant,
           aslope, diagonal, slanted, slanting, sloped,
           sloping]